Are Solar Panels worth it now?

[Tony K]

Hi all, hoping to tap in to some experience / knowledge on this subject.

 

I hope to break ground on my new self build house after Xmas. It will be small (110m2 approx) but has a south facing pitched roof which I estimate could host about 17m2 of panels.

I have been searching for generic cost/benefit calculations, and most of them seem so suggest that domestic panels are reliant upon FIT etc to make the panels pay for themselves inside of 20-30 years. One fairly well researched article went so far as to suggest that in the absence of FIT, the panels may not pay for themselves at all based on electricity bill savings alone.

 

In addition to the above, I have seen some articles suggesting that 17m2 is just too small a surface area to make panels worthwhile, making me doubt the wisdom of installing them at all. 

 

We aim to stay in the house for a long time, and so I can play the long game and am happy to invest in good kit upfront. I am aware that as prices from the grid go up over time, the investment in panels will perhaps become a better one, but I would still like some guidance on whether, if all things remain as they are now, I would be making a sensible investment by installing panels. 

 

I am working on the basis of PV panels feeding a battery, by the way. 

 

Thanks for any assistance!

 

[ProDave]

This has been discussed before.

 

First thing, if you are not getting the FIT, then do NOT get them installed by an MCS contactor. You will pay over the odds.

 

You can buy a 4Kwp system for about £2000 at the moment, just get an electrician to connect it all.

 

The key to making it worthwhile is near 100% self usage. Simple things like use large appliances washing machine, dishwasher, tumble dryer) one at a time in the daytime. Easier if you are retired or work from home but can be achieved with timers.

 

Second thing is have a hot water system with a tank (or a sun amp) i.e NOT a combi boiler. This will enable you to divert excess PV not being used to water heating.

 

And later on (I am not convinced the economics are there yet) is battery storage.

 

Also think about panel orientation.  All facing due south is not necesarilly best.  A mix of E, S and W would give more generation over a longer part of the day so more likely to be self used, than all S that will give a big mid day peak that you might not so easily be able to self use.

 

If you can even save a modest £200 per year off your electricity bill the payback would be 10 years.

[Triassic]

22 minutes ago, ProDave said:

buy a 4Kwp system for about £2000 at the moment, just get an electrician to connect it all.

Don’t forget that’s only for the panels, you’ll need a roof kit of some sort, an inverter, isolators etc.

[Stones]

Whilst you may be able to buy a Solar PV package for circa £2K, you'll still need to be on or in roof mounts, a diversion device (if using excess to heat DHW), a replacement inverter after 10 years, Labour for fitting(if not doing it yourself) and an electrician.  £2K becomes £3500 quite easily.  Of the various people I know with PV, they consume about 25% of what they generate.  We had a heat pump in our last house and managed to use about 40% of what we generated.  To use the rest you need to divert to DHW or other large load (electric car, storage heater). There's only so much you can divert to DHW and you may well find you still have excess in the peak of summer.

 

When I looked at it for our current house, MCS install prices were too high, and a non MCS system as above, factoring in electricity bill savings, and DHW offset (otherwise heated by an ASHP) struggled to pay for itself with a 17 year payback.  

 

 

[ProDave]

16 minutes ago, Triassic said:

Don’t forget that’s only for the panels, you’ll need a roof kit of some sort, an inverter, isolators etc.

The ones I was looking at on ebay include the inveter panels and on roof mounting kit e.g this one https://www.ebay.co.uk/itm/173540599051?ViewItem=&item=173540599051

[Jeremy Harris]

29 minutes ago, ProDave said:

The ones I was looking at on ebay include the inveter panels and on roof mounting kit e.g this one https://www.ebay.co.uk/itm/173540599051?ViewItem=&item=173540599051

 

If you click on the "See Full Item Description" button you get this link: http://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=173540599051&t=0&tid=310&category=41981&seller=energystore3&excSoj=1&excTrk=1&lsite=3&ittenable=false&domain=ebay.co.uk&descgauge=1&cspheader=1&oneClk=1&secureDesc=0

 

That makes it clear that the kit only includes 12 panels plus the fitting instructions.  Bit deceptive having the inverter and mounting kit in the eBay photo, though.

 

The same supplier does have a listing for a complete kit, 16 panels, mounting frames, inverter, cabling etc: https://www.ebay.co.uk/itm/PLUG-IN-Solar-4kW-4000W-PV-Panel-Kit-System-for-House-Self-Sufficient-DIY/172785554836?hash=item283ad25594:g:U2sAAOSwUFtZaInN  but the price is £3,995

[Triassic]

I’ve just emailed the company behind the eBay offering, asking for a price for everything necessary for an in-roof, all black system, including an inverter to allow a 50:50 split over a south and west facing door. Let’s see what the final price is!

[ProDave]

41 minutes ago, JSHarris said:

 

If you click on the "See Full Item Description" button you get this link: http://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=173540599051&t=0&tid=310&category=41981&seller=energystore3&excSoj=1&excTrk=1&lsite=3&ittenable=false&domain=ebay.co.uk&descgauge=1&cspheader=1&oneClk=1&secureDesc=0

 

That makes it clear that the kit only includes 12 panels plus the fitting instructions.  Bit deceptive having the inverter and mounting kit in the eBay photo, though.

 

The same supplier does have a listing for a complete kit, 16 panels, mounting frames, inverter, cabling etc: https://www.ebay.co.uk/itm/PLUG-IN-Solar-4kW-4000W-PV-Panel-Kit-System-for-House-Self-Sufficient-DIY/172785554836?hash=item283ad25594:g:U2sAAOSwUFtZaInN  but the price is £3,995

Oh that's sneaky. Hadn't noticed that. but I am sure I have seen others at least including the inverter for £2K.  Mine will be ground mounted probably on a home made mount (which will form a shed roof) so minimal cost there.

 

Re payback times, a 4Kw[ system will generate something like 3100KWh per year. Even if you only use half that, it will reduce your electricity bill by 1550 units per year, which at 14p per KWh is a £217 saving.  If you can get close to 100% usage, the saving will be getting close to £400 per year.

[ToughButterCup]

12 hours ago, ProDave said:

[...]

The key to making it worthwhile is near 100% self usage. Simple things like use large appliances washing machine, dishwasher, tumble dryer) one at a time in the daytime. Easier if you are retired or work from home but can be achieved with timers.

 

Second thing is have a hot water system with a tank (or a sun amp) i.e NOT a combi boiler. This will enable you to divert excess PV not being used to water heating.

 

And later on (I am not convinced the economics are there yet) is battery storage.

[...]

 

Wot Dave said.

We are either retired or about to. That makes using our own power easier

[Gone West]

14 hours ago, Tony K said:

In addition to the above, I have seen some articles suggesting that 17m2 is just too small a surface area to make panels worthwhile, making me doubt the wisdom of installing them at all. 

 

We also are procrastinating about whether it would be worthwhile fitting PVs on a similar sized area. Our electricity usage during April to September is just over 1kWh a day. If we had an EV we would fit them but is it worth it when most of the electricity would be exported to the grid. Everyone seems to think a PH should have PVs and are surprised we don't.

[Tony K]

1 hour ago, PeterStarck said:

We also are procrastinating about whether it would be worthwhile fitting PVs on a similar sized area. Our electricity usage during April to September is just over 1kWh a day. If we had an EV we would fit them but is it worth it when most of the electricity would be exported to the grid. Everyone seems to think a PH should have PVs and are surprised we don't.

 

Peter - what data / clacs have you used to guide you in your procrastination, and has the detailed advice offered by ProDave (for which thanks) affected your decision?

 

It sounds like there is not-insignificant care required when purchasing, installing, designing and even using panels in order for them to be worthwhile. 

 

[Stones]

For me it was simply the case of working out what it would cost to install vs return, i.e. how many years would it take for the savings made on energy bills to pay off the installation cost.  

 

My experience of PV, and others I have known gave me a baseline of likely PV generated consumption.  From there I looked at heating DHW.  I also factored in the simple fact that in summer, when potentially generated 30 kWh a day, I wouldn't be able to use it all, as daily use and DHW combined requirement (for us) are less than 30kWh per day.  With no other means of using the excess it would be exported (without recompense).  I costed the saving of heating DHW by means of PV against heating using my primary source (ASHP), i.e. applying the COP of 2.4

[mike2016]

Some costs savings are possible with "in roof" panels for new builds to save cost of some tiles/slates

You can also check out a ground mount out the back garden, cheaper to install yourself and get electrician to wire up afterwards. 

Keep an eye out for second hand panels and inverters also

Check out batteries in 2-3 years for better prices

My Plan:

2.5kW in roof panels in new build (new)

2.5kW rear garden with mix of s/w/e facing panels (second hand)

Batteries later....

That's if I get the build going..! 

[Triassic]

9 minutes ago, mike2016 said:

Some costs savings are possible with "in roof" panels for new builds to save cost of some tiles/slates

The 16 panels on my roof will save me £1,200 in slates. This does not include labour for fitting the slates. A quick check suggests the labour element of fixing 26m2 of slates is £2,800 

[Jeremy Harris]

There is definitely a cost saving by going for in-roof, over on-roof, that's worth taking into account.  For us, the cost saved in not having to purchase and have fitted slates for the area covered by the in-roof panels was around £2.5k.  We were lucky, in that we got in before the last FIT rate cut, so we get around £1000 a year from generation and deemed export payments, plus the Sunamp is able to store excess PV pretty efficiently for DHW, so we're on-track to recover the capital cost of our system after around 7 years or so, which seems reasonable.

 

If fitting a system now I think I'd still go for the same setup, but reduce the cost by not having an MCS approved system.  The repayment time would probably end up being a fair bit longer, but with battery storage prices dropping fairly sharply, plus the fact that I've already got a plug-in hybrid, I'm likely to be better placed to use more of our self-generated energy in future.

[Tony K]

8 minutes ago, Triassic said:

The 16 panels on my roof will save me £1,200 in slates. This does not include labour for fitting the slates. A quick check suggests the labour element of fixing 26m2 of slates is £2,800 

 

Mine is a new build and I had anticipated setting panels into the roofslope, and so had thought about the savings in terms of slates and roofing labour.

 

It does occur to me though that the sections of roof under the panels will need to be treated with something (GRP perhaps?) which will have a cost, including labour. It won't be anything like the cost of posh slates, but it is to be factored in, especially if it makes the roof carcass more complex, as that may increase the roofers price to put it all together..... Perhaps?

 

All in all, it seems to me that I have very little to lose by sticking in PVs. If I shop around for best prices (including Mikes idea of some second hand ones) and am careful with the initial outlay, then even if I never quite master the disciplines of most effective self use as set out by ProDave, the panels will contribute something at least over their lifetimes. Even if that never quite reaches the initial outlay cost, I'd be pretty unlucky for it to fall far short. 

 

Given the potential benefits, the panels seem a risk well worth taking. 

[Triassic]

The panels sit in an off the shelf tray, costing around £80 per panel.

 

[Tony K]

16 minutes ago, Triassic said:

The panels sit in an off the shelf tray, costing around £80 per panel.

 

 

That's neat and tidy.

 

Which shelf did they come off of please? The look like they just go straight on top of sheet timber?

[Jeremy Harris]

They look very similar to the GSE Integration trays we used, but may be another make.  Easy Roof trays look similar.

[Triassic]

20 hours ago, Triassic said:

I’ve just emailed the company behind the eBay offering, asking for a price for everything necessary for an in-roof, all black system, including an inverter to allow a 50:50 split over a south and west facing door. Let’s see what the final price is!

So here is the reply... NOTE is asked for a quote for a 4KW in roof system, they quoted for a 3kw system!!!

 

We could supply the following IN-ROOF 3kWp Solar PV Kit systems;

 

Solar PV Kit Options

14 x Canadian Solar Mono 280W (All Black) solar panels

1 x Solis 4.0kW Dual tracker inverter

1 x GSE Integration in-roof mounting kit (2 rows of 3 in portrait and 2 rows of 4 in portrait)

1 x All cables, clips, generation meter, AC/DC isolators

1 x Delivery to site

£3,995 inc VAT

As above but using 14 x JA Solar 295W (All Black) solar panels for £4,195 inc VAT

As above but using 14 x QCells 305W (All Black) solar panels for £4,295 inc VAT

 

Optional Extras

Geo Solo 2 Wireless Display - £145 inc VAT

iBoost Immersion control unit - £345 inc VAT

[Alexphd1]

That's not cheap. 

[Guest Alphonsox]

37 minutes ago, Triassic said:

So here is the reply... NOTE is asked for a quote for a 4KW in roof system, they quoted for a 3kw system!!!

 

These are all 4kw systems give or take.

[Gone West]

6 hours ago, Tony K said:

 

Peter - what data / clacs have you used to guide you in your procrastination...

 

If we were to fit PVs we would want all black panels with micro inverters which is not the cheapest system. I used PVGIS to estimate output many years ago when we started our build but our electricity usage is lower than we had anticipated hence the doubt about fitting them. If we ever sold the house it would seem that PVs would be expected so we are still wondering.

[Adamantium]

I’m on the verge of doing this too.

 

I’m looking at 17 305w panels on top of a flat roof for £6850 exc vat (new build) inc iboost and solaredge inverters.

 

no scaffolding or structural surveys required since already in place.

 

mine will be installed around feb/March when there may be no FIT available anyway.

 

I'm thinking I could be saving loads by going for a non mcs installed now.

 

any recommendations?

 

can I expect to save much?

 

the current quoting company have been very specific about insisting on tier 1 quality panels when comparing quotes but I’m struggling to find another decent company to quote for the Hertfordshire area.

[PeterW]

About £2k over price. You should be aiming at £1/W installed.